<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>注册页面</title>
</head>
<style>
    .form-group {
margin-bottom: 1.5rem;
}
label {
display: block;
margin-bottom: 0.5rem;
font-weight: 500;
color: #333;
}
#phone {
width: 100%;
padding: 0.8rem;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 1rem;
box-sizing: border-box;
transition: border-color 0.3s, box-shadow 0.3s;
}
#phone:invalid {
border-color: #ff4444;
box-shadow: 0 0 2px rgba(255, 68, 68, 0.2);
}
#phone:focus {
outline: none;
border-color: #2196F3;
box-shadow: 0 0 0 2px rgba(33, 150, 243, 0.2);
}
button {
width: 100%;
padding: 0.8rem;
border: none;
border-radius: 4px;
background-color: #2196F3;
color: white;
font-size: 1rem;
cursor: pointer;
transition: background-color 0.3s;
}
button:hover {
background-color: #1976D2;
}
.form-container {
max-width: 400px;
padding: 2rem;
border: 1px solid #eee;
border-radius: 8px;
box-shadow: 0 0 10px rgba(0, 0, 0, 0.05);
}
.page-container {
height: 300px;
display: flex;
align-items: center;
justify-content: center;
}
.form-container {
flex-grow: 1;
}
</style>
<body>
    <div class="page-container">
        <div class="form-container">
        <form action="#" method="get">
        <div class="form-group">
        <label for="phone">手机号码</label>
        <input autocomplete="off"
        autofocus
        required
        name="phone" id="phone"
        placeholder="请输入手机号"
        pattern="^1[3-9]\d{9}$"
        title="请输入有效的手机号（11位数字，以13/14/15/17/18/19开头）"
        type="tel">
        </div>
        <button>注册</button>
        </form>
        </div>
        </div>
</body>
</html>